Processing of images of interventional instruments with markers

Abstract

A method and an image processing system for the evaluation of projection images generated by an X-ray imaging system, wherein the images may show different instruments of a given set of interventional instruments like catheters or guide wires. The instruments are equipped with markers such that their configuration is characteristic of the corresponding instrument. Preferably three markers are arranged on a straight line, the ratio of the distances between them being characteristic for the corresponding instrument. The image processing system may then identify the instruments present in a given projection and provide functionalities for a user that correspond to said instruments. Moreover, the system may be used to locate an instrument of interest in a projection image if the marker configuration of that instrument is known a priori.

The invention claimed is: 
     
       1. An image processing system for evaluation of projection images of a body volume including at least one instrument of a plurality of interventional instruments, the image processing system comprising:
 a plurality of markers affixed to each of the plurality of instruments in a configuration that provides a ratio of distances between the markers characteristic of an instrument on which the markers are affixed; and 
 a processor configured to
 detect the markers of the at least one of the plurality of instruments on a projection image; 
 identify uniquely which ones of the plurality of instruments corresponds to the at least one instrument in the projection image from the ratio of distances between the detected markers; and 
 change an operating mode of the image processing system automatically in dependence on which of the plurality of instruments is uniquely identified in the projection image. 
 
 
     
     
       2. The image processing system according to  claim 1 , wherein at least some markers comprise different shapes that can be discriminated on the projection image. 
     
     
       3. The image processing system according to  claim 1 , wherein at least two of the instruments carry three or more markers that are attached to said instruments in different configurations. 
     
     
       4. The image processing system according to  claim 1 , wherein the markers are opaque with respect to X-radiation. 
     
     
       5. The image processing system according to  claim 1 , comprising a data base in which data about the markers and their configurations is stored for the plurality of instruments. 
     
     
       6. The image processing system according to  claim 5 , wherein the image processing system is adapted to localize an instrument of interest on the projection image from the data about the markers and/or their configuration for said instrument and identifying data supplied by a user related to the instrument of interest. 
     
     
       7. The image processing system according to  claim 1 , wherein the image processing system is adapted to provide operations of the image processing system that are specific for the identified at least one instrument in the projection image. 
     
     
       8. The image processing system according to  claim 5 , wherein the image processing system is adapted to refine the localization of an instrument with the help of the data about the markers and/or their configuration for said instrument. 
     
     
       9. The image processing system according to  claim 1 , wherein the plurality of markers on at least two of the instruments comprise three or more markers that are attached to said instruments in a substantially straight line. 
     
     
       10. The image processing system according to  claim 9 , wherein the at least one instrument in the projection image is identified from a ratio of distances between the three or more markers including intermediate markers that include other markers on each direction of the substantially straight line and outside markers that include other markers only in one direction of the substantially straight line. 
     
     
       11. The image processing system according to  claim 10 , wherein the at least one instrument in the projection image is identified from a ratio of distances between outside markers and intermediate markers. 
     
     
       12. The image processing system according to  claim 1 , wherein the processor is configured to indicate the unique identification in the projection image. 
     
     
       13. The image processing system according to  claim 1 , wherein the processor is configured to indicate the unique identification in the projection image by different colors or labels. 
     
     
       14. The image processing system according to  claim 1 , wherein the processor is configured to distinguish different instruments in the projection image based on which of the plurality of instruments is identified in the projection image. 
     
     
       15. A method for evaluation by an image processing system of projection images of a body volume including at least one instrument of a plurality of interventional instruments, the method comprising acts of:
 attaching a plurality of markers to each of the plurality of instruments in a configuration that provides a ratio of distances between the markers characteristic of the instrument on which the markers are affixed; 
 detecting the markers of the at least one of the plurality of instruments in a projection image; 
 identifying uniquely which ones of the plurality of instruments corresponds to the at least one instrument in said projection image from the ratio of distances between the detected markers; and 
 automatically activating a specific image processing functionality in dependence on which of the plurality of instruments is identified in said projection image. 
 
     
     
       16. An image processing system for evaluation of projection images of a body volume including at least one instrument of a plurality of interventional instruments, the image processing system comprising:
 a plurality of markers affixed to each of the plurality of instruments in a configuration that provides a ratio of distances between the markers characteristic of an instrument on which the markers are affixed; and 
 a processor configured to
 detect the markers of the at least one of the plurality of instruments on a projection image; 
 identify uniquely which ones of the plurality of instruments corresponds to the at least one instrument in the projection image from the ratio of distances between the detected markers; and 
 indicate the unique identification in the projection image. 
 
 
     
     
       17. The image processing system according to  claim 16 , wherein the processor is configured to indicate the unique identification in the projection image by different colors or labels. 
     
     
       18. The image processing system according to  claim 16 , comprising a data base in which data about the markers and their configurations is stored for the plurality of instruments. 
     
     
       19. The image processing system according to  claim 16 , wherein the processor is configured to change the operating mode of the image processing system by automatically enabling a context sensitive menu in the user interface in dependence on which of the plurality of instruments is uniquely identified in the projection image. 
     
     
       20. The image processing system according to  claim 16 , wherein the processor is configured to change the operating mode of the image processing system by automatically adapting settings of image processing functionality in dependence on which of the plurality of instruments is uniquely identified in the projection image.